Self-adjusting torque device

ABSTRACT

There is provided a self-adjusting torque device which includes a driving module, a driven module and an adjusting module. The driving module is connected to a power inputting apparatus and has an acting force which is a first tension generated by the power inputting apparatus. The driven module is connected to a winding material and has an acting force which is a second tension applied on the winding material. The adjusting module is connected to the driving module and the driven module, and adjusts a distance between the driving module and the driven module according to the second tension force so as to keep the second tension identical with the first tension.

BACKGROUND OF THE INVENTION

The present invention relates to a self-adjusting torque device.

During production process, some raw/auxiliary materials are fed andrecovered in a winding form. In the course of feeding and recovering ofa winding material, a torque of a driving motor M (M=R×F) is maintainedconstant. Since a radius R of the winding material varies with thefeeding of the material, a tension F of the material is changedaccordingly, which affects the accuracy of the feeding of material.

FIG. 1 is a diagram illustrating a tension variation during the courseof feeding and recovering of a winding material in the related art. Atan initial stage, the radius R1 of the winding material is the largest,while the tension F1 is the smallest; after an operation of a period oftime, the radius R2 of the winding material is decreased, and thetension F2 is increased where the torque M is kept unvaried.

A known approach for solving the above problem is to provide threeradius detecting sensors beside the material roll with each sensorcorresponding to a respective predetermined radius. For example, a firstsensor corresponds to a radius R1, a second sensor corresponds to aradius R2, and a third sensor corresponds to a radius R3. When the threesensors are triggered simultaneously, the motor outputs a torqueM1=R1×F; when the second and the third sensors are triggered, the motoroutputs a torque M2=R2×F; and when only the third sensor is triggered,the motor outputs a torque M3=R3×F. Thus, following the variation of theradius of the winding material (for example, R1, R2 and R3,respectively), the torque is varied accordingly (for example, M1, M2 andM3, respectively), so as to keep the tension F constant.

In the above approach, the variation of the torque suffers from abruptchanges; that is to say, the differences between the torques M1 and M2and between M2 and M3 are very great, and thus a smooth and gradualchange is not available. In addition, when the radius of the windingmaterial is in a range between R1 and R2 or between R2 and R3, thetension F will continue to vary with the change of the radius and stillresults in inaccuracy of feeding and recovering of the winding material.

SUMMARY OF THE INVENTION

According to an embodiment of the present invention, a self-adjustingtorque device is provided, which includes a driving module connected toa power inputting apparatus and having an acting force which is a firsttension generated by the power inputting apparatus; a driven moduleconnected to a winding material and having an acting force which is asecond tension applied on the winding material; an adjusting moduleconnected to the driving module and the driven module and adjusting adistance between the driving module and the driven module according tothe second tension so as to keep the second tension identical with thefirst tension.

In the embodiment of the present invention, it is possible toautomatically adjust the torque of a winding material feeding orrecovering device, keep a tension of the winding material feeding orrecovering device constant and thereby guarantee the accuracy of feedingor recovering the material.

Further scope of applicability of the present invention will becomeapparent from the detailed description given hereinafter. However, itshould be understood that the detailed description and specificexamples, while indicating preferred embodiments of the invention, aregiven by way of illustration only, since various changes andmodifications within the spirit and scope of the invention will becomeapparent to those skilled in the art from the following detaileddescription.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from thedetailed description given hereinafter and the accompanying drawingswhich are given by way of illustration only, and thus are not limitativeof the present invention and wherein:

FIG. 1 is a diagram illustrating a tension variation during the courseof feeding and recovering winding material in the related art;

FIG. 2 is a diagram illustrating a configuration of a self-adjustingtorque device according an embodiment of the present invention;

FIG. 3 is a diagram illustrating a configuration of a first example of aself-adjusting torque device according to an embodiment of the presentinvention; and

FIG. 4 is a diagram illustrating a configuration of a second example ofa self-adjusting torque device according to an embodiment of the presentinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The implementations of the present invention provide a self-adjustingtorque device so as to address the problem that the tension is notstable during feeding or recovering of a winding material in the relatedart, realize automatic adjustment of the torque of a material feeding orrecovering device, keep the tension stable and guarantee accuracy offeeding or recovering the material.

FIG. 2 is a diagram illustrating a self-adjusting torque deviceaccording to an embodiment of the present invention. As shown in FIG. 2,the self-adjusting torque device includes: an driving module 1 forintroducing an external power and having a first tension; a drivenmodule 2 connected to a winding material, reflecting a second tensionacting on the winding material; and an adjusting module 3 connected toboth of the driving module 1 and the driven module 2, for receiving thefirst and the second tensions and self-adjusting the second tension tokeep it consistent with the first tension.

In the present embodiment, it is possible to self-adjust a torque of awinding material feeding and recovering device, so as to keep a tensionon the winding material feeding and recovering device constant, therebyguaranteeing the accuracy of the feeding and recovering of the material.

FIG. 3 is a diagram illustrating a configuration of a first example of aself-adjusting torque device according to the embodiment of the presentinvention. As shown in FIG. 3, the self-adjusting torque deviceincludes: a driving module comprising a first driving screw 11, seconddriving screw 12, and a third driving screw 13; a driven screw 2 servingas a driven module; and an electromagnetic torque device 3 serving as anadjusting module. The first driving screw 11, the second driving screw12, and the third driving screw 13 are mounted on respective axesthrough bearings, and the driven screw 2 is movable on its axis within apredetermined range. The left side of the first driving screw 11 isconnected to a motor, so as to start the winding material feeding andrecovering device. After the device is started, a rotating speed of thefirst driving screw 11 is set to nil, and the first driving screw 11drives the second driving screw 12 to rotate through engagement. Sincethe first driving screw 11 and the second driving screw 12 are bothsecured with bearings, that is, their positions both are fixed, thesecond driving screw 12 has a rotating speed that is substantially thesame as the rotating speed of the first rotating screw 11, i.e., n1,after the second driving screw 12 is driven to rotate by the firstdriving screw 11. Since the relative position of the third driving screw13 with respect to the second driving screw 12 is also fixed (the axeson which the second driving screw 12 and the third driving screw 13 aremounted can be fixed, or the second driving screw 12 and the thirddriving screw 13 can be provided on the same axis), the third drivingscrew 13 has a rotating speed that is substantively the same as therotating speed of the second driving screw 12, i.e., n1. The drivenscrew 2 engaged with the third driving screw 13 has its right sideconnected to the winding material, and the driven screw 2 is notsecurely fixed on an axis but movable forward and backward within apredetermined distance. The rotating speed of the driven screw 2 is setto n2. When the rotating speed n2 of the driven screw 2 is larger thanthe rotating speed n1 of the third driving screw 13, the driven screw 2moves towards the right side (a direction towards the winding material);when the rotating speed n2 of the driven screw 2 is less than therotating speed n1 of the third driving screw 13, the driven screw 2moves towards the left side (a direction away from the windingmaterial); and when the rotating speed n2 of the driven screw 2 is equalto the rotating speed n1 of the third driving screw 13, a relativeposition of the third driving screw 13 is fixed. The above conditionscan be satisfied by designing pitches and directions of the threads ofthe third driving screw 13 and the driven screw 2 to make themconsistent.

The electromagnetic torque device 3 transfers torques throughelectromagnetic forces. That is, one end of the electromagnetic torquedevice is an electromagnetic N pole, the other end is an S pole, and thetwo ends are facing with each other with a distance L therebetween. Onthe basis of “attraction for opposite poles” principle, when the N polerotates, the S pole rotates with it, and a transferring torque M betweenthe N pole and the S pole is inversely proportional to the distance L,so that the larger the distance L is, the smaller the transferred torqueM is, and vice versa.

The self-adjusting torque device for winding material is operated asfollows.

The left side of the first driving screw 11 is connected to the motor toreceive power from the motor so as to starting the device. The motordrives the first driving screw 11 to rotate at a rotating speed of n1.Since the second driving screw 12 is engaged with the first drivingscrew 11, and the first and the second driving screws 11 and 12 arefixed, the first driving screw 11 drives the second driving screw 12 torotate, and the second driving screw 12 has a rotating speed that is thesame as the rotating speed of the first driving screw 11, i.e., n1.

The right side of the first driving screw 11 is connected to theelectromagnetic torque device, and the electromagnetic torque devicetransfers a torque M from its left end connected to the first drivingscrew 11 to the right end thereof. Suppose that at this time, a distancebetween the left and the right ends of the electromagnetic torque deviceis L, the torque received by the right end from the left end of theelectromagnetic torque device is M1 (the acting force on the right endis the second tension F1), and the rotating speed of the driven screw 2,which is driven by the torque M1 from the right end to rotate, is n2.

If the rotating speed n2 of the driven screw 2 is less than the rotatingspeed n1 of the third driving screw 13 (the second tension F1 applied onthe driven screw 2 is less than the first tension F applied on the firstdriving screw 11), the driven screw 2 moves towards the left side, andthe distance L of the electromagnetic torque device decreases. Thus, thetorque M1 transferred form the left end to the right end becomes larger,and the second tension F1 applied on the driven screw 2 becomes larger,until the rotating speed n2 of the driven screw 2 is equal to therotating speed n1 of the third driving screw 13, the rotating speeds ofthe driven screw 2 and the driving screw 13 become identical, and theirrelative positions are fixed. At this time, the second tension F1applied on the driven screw 2 is equal to the first tension F applied onthe first driving screw 11, and then it is realized to self-adjust thetorque M1 and keep the second tension F1 applied on the driven screw 2constant (F1=F). When the radius of the winding material decreases(changing from R1 to R2), the second tension F1 increases gradually.Since the second tension F1 is also applied on the driven screw 2, thesecond tension F1 increases, and the rotating speed n2 of the drivenscrew 2 increases with it. When the rotating speed of the driven screw 2is larger the rotating speed n1 of the third driving screw 13, thedriven screw 2 moves towards the right side, and the distance L betweenthe two ends of the electromagnetic torque device increases. Since thedistance L increases, the torque M1 decreases, and thus the secondtension F1 applied on the driven screw 2 also decreases gradually, untilthe second tension F1 is equal to the first tension F.

In the present example, the rotating speeds of the first driving screw11, the second driving screw 12, and the third driving screw 13 areidentical, i.e., n1, which reflects the magnitude of the first tensionF. The rotating speed n2 of the driven screw 2 reflects the magnitude ofthe second tension F1. When the first tension F and the second tensionF1 are not identical, the driven screw 2 moves towards left or right,until the rotating speeds of n1 and n2 become identical, so as toautomatically adjust the torque applied on the driven screw 2, that is,to automatically adjust the second tension F1 applied on the drivenscrew 2, so as to keep the second tension F1 identical with the firsttension F.

In the present example, the driving module may comprise a first drivengear, a second driving gear, and a third driving screw. The firstdriving gear and the second driving gear may mesh with each other, ormay be coupled through a chain, so long as the rotating speeds of thefirst driving gear and the second driving gear can be kept identical. Inthe present example, the driving module may also comprise a firstdriving rotary wheel, a second driving rotary wheel, and a third drivingscrew. The first driving rotary wheel and the second driving rotarywheel are coupled by a belt, so as to keep the rotating speeds of thefirst and the second driving rotary wheels identical. The operatingprinciple of the mechanism is also as discussed above.

FIG. 4 is a diagram illustrating a configuration of a second example ofa self-adjusting torque device according to the embodiment of thepresent invention. As shown in FIG. 4, the self-adjusting torque deviceof the present example differs from that of the first example in that:the first driving screw 11 of the driving module is movable, theposition of the driven screw 2 serving as the driven module is fixed,while the positions of the second and the third driving screw 12, 13 ofthe driving module are kept unchangeable. In this case, the driven screw2 brings the second and the third driving screws 12, 13 to rotate, thatis, the rotating speeds of the second and the third driving screws 12,13 are identical with that of the driven screw 2. When the rotatingspeed n2 of the driven screw 2 is larger than the rotating speed n1 ofthe first driving screw 11 (the second tension F1 is larger than thefirst tension F), the driving screw 11 moves towards left, and thedistance L increases. As a result, the torque transferred by theelectromagnetic torque device decreases, that is, M1 decreases, untilthe second tension F1 is equal to the first tension F. When the rotatingspeed n2 of the driven screw 2 is less than the rotating speed n1 of thefirst driving screw 11 (the second tension F1 is less than the firsttension F), the driving screw 11 moves towards right, and the distance Lbetween the ends of the electromagnetic torque device decreases. As aresult, the torque transferred by the electromagnetic torque deviceincreases, that is, M1 increases, until the second tension F1 is equalto the first tension F.

In the present example, the rotating speeds of the driven screw 2, thesecond driving screw 12, and the third driving screw 13 are identical,i.e., n2, which reflects the magnitude of the second tension F1. Therotating speed n1 of the first driving screw 11 reflects the magnitudeof the first tension F. When the first tension F and the second tensionF1 are not identical, the first driving screw 11 moves toward left orright, until the rotating speeds n1, n2 become identical, so as toautomatically adjust the torque applied on the driven screw 2, that is,to automatically adjust the second tension F1 applied on the drivenscrew 2, so as to keep the second tension F1 identical with the firsttension F.

In the present example, the driving module may also comprise a firstdriving screw, a second driving screw, and a third driving gear, and adriven gear may be used as the driven module. The third driving gear andthe driven gear can mesh with each other, or be coupled through a chain,so long as the rotating speeds of the third driving gear and the drivengear can be kept identical. In the present example, the driving modulemay also comprise a first driving screw, a second driving screw, and athird driving rotary wheel, and a driven rotary wheel can be used as thedriven module. The third driving rotary wheel and the driven rotarywheel are coupled by a belt, so as to keep the rotating speeds of thethird driving rotary wheel and the driven rotary wheel identical. Theoperating principle of the mechanism is also as discussed above.

The first and the second examples of the self-adjusting torque deviceaccording to the embodiment of the present invention automaticallyadjust the torque applied on the winding material by coupling the twoends of the electromagnetic torque device to a fixed screw and a movablescrew, respectively. Based on the principle that the magnitude of theforce applied on the material is in direct proportion to the rotatingspeed of the screw connected to the material, while the torquetransferred by the electromagnetic torque device is in reverseproportion to the distance between the two ends of the electromagnetictorque device, the torque applied on the winding material can beadjusted automatically, the force applied on the material can be keptconstant, and the accuracy of feeding or recovering material can beguaranteed.

The invention being thus described, it will be obvious that the same maybe varied in many ways. Such variations are not to be regarded as adeparture from the spirit and scope of the invention, and all suchmodifications as would be obvious to those skilled in the art areintended to be included within the scope of the following claims.

1. A self-adjusting torque device, including: a driving module connectedto a power inputting apparatus and having an acting force which is afirst tension generated by the power inputting apparatus; a drivenmodule connected to a winding material and having an acting force whichis a second tension applied on the winding material; and an adjustingmodule connected to the driving module and the driven module andadjusting a distance between the driving module and the driven moduleaccording to the second tension so as to keep the second tensionidentical with the first tension.
 2. The self-adjusting torque device ofclaim 1, wherein the driving module includes a first driving screw, asecond driving screw, and a third driving screw that have fixedpositions, the first driving screw and the second driving screw meshwith each other, the second driving screw and the third driving screware connected with each other and have identical rotating speeds, and afront end of the first driving screw is connected to the power inputtingapparatus; the driven module includes a driven screw having a movableposition, and the driven screw meshes with the third driving screw andis connected to the winding material at a rear end of the driven screw;and the adjusting module includes an electromagnetic torque device, oneend of the electromagnetic torque device is connected to a rear end ofthe first driving screw, and the other end is connected to a front endof the driven screw.
 3. The self-adjusting torque device of claim 1,wherein the driving module includes a first driving screw having amovable position and a second driving screw and a third driving screwthat both have fixed positions, the first driving screw and the seconddriving screw mesh with each other, the second driving screw and thethird driving screw are connected with each other and have identicalrotating speeds, and a front end of the first driving screw is connectedto the power inputting apparatus; the driven module includes a drivenscrew having a fixed position, and the driven screw meshes with thethird driving screw and is connected to the winding material at a rearend of the driven screw; and the adjusting module includes anelectromagnetic torque device, one end of the electromagnetic torquedevice is connected to a rear end of the first driving screw, and theother end is connected to a front end of the driven screw.
 4. Theself-adjusting torque device of claim 1, wherein the driving moduleincludes a first driving gear, a second driving gear, and a thirddriving screw that have fixed positions, the first driving gear and thesecond driving gear mesh with each other, the second driving gear andthe third driving screw are connected with each other and have identicalrotating speeds, and a front end of the first driving gear is connectedto the power inputting apparatus; the driven module includes a drivenscrew having a movable position, and the driven screw meshes with thethird driving screw and is connected to the winding material at a rearend of the driven screw; and the adjusting module includes anelectromagnetic torque device, one end of the electromagnetic torquedevice is connected to a rear end of the first driving gear, and theother end is connected to a front end of the driven screw.
 5. Theself-adjusting torque device of claim 1, wherein the driving moduleincludes a first driving screw having a movable position and a seconddriving screw and a third driving gear that both have fixed positions,the first driving screw and the second driving screw mesh with eachother, the second driving screw and the third driving gear are connectedwith each other and have identical rotating speeds, and a front end ofthe first driving screw is connected to the power inputting apparatus;the driven module includes a driven gear having a fixed position, andthe driven gear meshes with the third driving gear and is connected tothe winding material at a rear end of the driven screw; and theadjusting module includes an electromagnetic torque device, one end ofthe electromagnetic torque device is connected to a rear end of thefirst driving screw, and the other end is connected to a front end ofthe driven screw.
 6. The self-adjusting torque device of claim 1,wherein the driving module includes a first driving rotary wheel, asecond driving rotary wheel, and a third driving screw that have fixedpositions, the first driving rotary wheel and the second driving rotarywheel are coupled by a belt, the second driving rotary wheel and thethird driving screw are connected with each other and have identicalrotating speeds, and a front end of the first driving rotary wheel isconnected to the power inputting apparatus; the driven module includes adriven screw having a movable position, and the driven screw meshes withthe third driving screw and is connected to the winding material at arear end of the driven screw; and the adjusting module includes anelectromagnetic torque device, one end of the electromagnetic torquedevice is connected to a rear end of the first driving rotary wheel, andthe other end is connected to a front end of the driven screw.
 7. Theself-adjusting torque device of claim 1, wherein the driving moduleincludes a first driving screw having a movable position and a seconddriving screw and a third driving rotary wheel that both have fixedpositions, the first driving screw and the second driving screw meshwith each other, the second driving screw and the third driving rotarywheel are connected with each other and have identical rotating speeds,and a front end of the first driving screw is connected to the powerinputting apparatus; the driven module includes a driven rotary wheelhaving a fixed position, the driven rotary wheel meshes with the thirddriving rotary wheel and is connected to the winding material at a rearend of the driven rotary wheel; and the adjusting module includes anelectromagnetic torque device, one end of the electromagnetic torquedevice is connected to a rear end of the first driving screw, and theother end is connected to a front end of the driven rotary wheel.
 8. Theself-adjusting torque device of claim 1, wherein the driving moduleincludes a first driving gear, a second driving gear, and a thirddriving screw that have fixed positions, the first driving gear and thesecond driving gear are coupled by a chain, the second driving gear andthe third driving screw are connected with each other and have identicalrotating speeds, and a front end of the first driving gear is connectedto the power inputting apparatus; the driven module includes a drivenscrew having a movable position, the driven screw meshes with the thirddriving screw and is connected to the winding material at a rear end ofthe driven screw; and the adjusting module includes an electromagnetictorque device, one end of the electromagnetic torque device is connectedto a rear end of the first driving gear, and the other end is connectedto a front end of the driven screw.
 9. The self-adjusting torque deviceof claim 1, wherein the driving module includes a first driving screwhaving a movable position and a second driving screw and a third drivinggear that both have fixed positions, the first driving screw and thesecond driving screw mesh with each other, the second driving screw andthe third driving gear are connected with each other and have identicalrotating speeds, and a front end of the first driving screw is connectedto the power inputting apparatus; the driven module includes a drivengear having a fixed position, the driven gear and the third driving gearis coupled by a chain and is connected to the winding material at a rearend of the driven gear; and the adjusting module includes anelectromagnetic torque device, one end of the electromagnetic torquedevice is connected to a rear end of the first driving screw, and theother end is connected to a front end of the driven gear.